Django：Django无法识别发布变量

Question

I'm probubly missing something very basic, but when I try to accsess a post varaible by means of: request['title'] in a function, I get this error:

Environment:


Request Method: GET
Request URL: http://127.0.0.1:8000/ajax/drafts/create

Django Version: 1.4
Python Version: 2.7.3
Installed Applications:
('django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'Knights',
 'django.contrib.admin')
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware')


Traceback:
File "/Library/Python/2.7/site-packages/Django-1.4-py2.7.egg/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/Library/Python/2.7/site-packages/Django-1.4-py2.7.egg/django/contrib/auth/decorators.py" in _wrapped_view
  20.                 return view_func(request, *args, **kwargs)
File "/Users/Mike/Desktop/Main/Django-Development/BBN/Knights/views.py" in document_create
  179.     title = request.POST['title']
File "/Library/Python/2.7/site-packages/Django-1.4-py2.7.egg/django/utils/datastructures.py" in __getitem__
  258.             raise MultiValueDictKeyError("Key %r not found in %r" % (key, self))

Exception Type: MultiValueDictKeyError at /ajax/drafts/create
Exception Value: "Key 'title' not found in <QueryDict: {}>"

The full code for the function is this:

def document_create(request):
    user = request.user
    title = request.POST['title']
    if (title != ''):
        Draft.objects.create(content='Your content goes here', user=user, title=title)

and the post variables listed are this:

POST:
title = u'sdff'

Edit: Also, when I list through the items with a for loop, the title variable comes up.

Answer 1

The request that caused the error was a GET, and you are trying to get the value of the title parameter from the POST dict. Change your code to:

def document_create(request):
    user = request.user
    title = request.GET['title']
    if (title != ''):
        Draft.objects.create(content='Your content goes here', user=user, title=title)

Or, you could test if the request is a GET or a POST, checking the request.method attribute.

Answer 2

Are you sure that your request is really a POST? For me it look like your are trying to retrieve data from a POST request but the query is in reality a GET request.

Also, you should use if 'title' in request.POST: to check the presence of the variable in request...

Regards

Etienne

Answer 3

Firstly, this is a GET query, so the POST dict will be empty. Did you mean to set method='POST' in your form element in the HTML?

Secondly, KeyError means the key wasn't in the POST dictionary. You should be doing:

title = request.POST.get('title', None)
if title is None:
    ...

This sets title to None if the key is not in request.POST .